Liquid Crystal – An Intermediate State – Its Applications in Latest Technology

(Last Updated On: October 11, 2019)

Evolution in Science & Technology

Heraclitus – a presocratic Greek philosopher said that “Change is the only constant in life” and this isn’t only a core belief of philosophy but also an invisible fundamental foundation on which we have built the science and technology since times immemorial. Science- bought about innumerable changes in the world we live in- itself changed over the centuries, and now is changing in spans of decades! This is something that amazes people which they often misinterpret as some amazing technology.

Television and mobile phones are the most commonly observed physical changes in our houses. The detailed technological side of this evolution is a topic for sometime later, today let me tell you about the evolution of television and mobile screens.

Liquid Crystal

We are all well aware of the three states of matter while an intermediate state- Liquid Crystal– is often left in the depths of science. Liquid Crystals or LCs are a state of matter which has properties between those of liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. These crystals have almost all the optical properties of solids due to the ordered arrangement of the lattice.

Molecule Arrangement in Solid, Liquid Crystal and Liquid
Molecules Arrangement in Solid, Liquid Crystal and Liquid

Liquid crystals are found both in the natural world and in technological applications.

In 1888, Austrian botanical physiologist Friedrich Reinitzer, observed the liquid crystals for the first time while examining the Physico-chemical properties of various derivatives of cholesterol. These were later known as Lyotropic liquid crystals- concentration-dependent – which are found in living systems like- proteins and cell membranes.

Friedrich Reinitzer
Friedrich Reinitzer (1857 – 1927)

Thermotropic liquid crystals- the one widely employed in modern technology- are those who exhibit different arrangements and different properties at different temperatures. They are broadly classified into three categories: Cholesteric liquid crystals, Smectic liquid crystals, and Nematic liquid crystals.

1. Cholesteric liquid crystals

  • The molecules are arranged parallel to each other within each layer and each layer is rotated to
    the layer above and below it.
  • They reflect different wavelengths based on their pitch.
  •  They are used in mood rings and mood balls.
  • Also employed in the manufacture of thermometers and some displays.

2. Smectic liquid crystals

  • They are ordered in two dimensions.
  • The molecules are arranged in layers.
  • They- naturally- form Super-hydrophobic surfaces as in lotus leaves.
  • They are also used in Illumination panel.

3. Nematic liquid crystals

  • Molecules are in one dimension with no organizations of rows and columns.
  • Molecules are parallel to each other.
  • Aligned by an electric field.
  • Very sharp and luminous- hence used in mobiles, calculators, portable computers, flat-screen TVs
    etc.
Various Types of Thermotropic Liquid Crystal
Various Types of Thermotropic Liquid Crystals

Also Read: The Beginning of Physics: The Presocratics (Part-1)

Applications of Liquid crystals

1. LCDs- Liquid crystals are widely used in the manufacture of television and mobile screens
because-

  • They emit a very sharp and bright light.
  • They consume less power than the older generation of displays.
  • It takes less space.
  • They are about 40% easier to carry.
Liquid Crystal in Mobile Phones
Liquid Crystal in Mobile Phones

2. Liquid Crystal Thermometers- used in measuring temperature-

  • Plastic strips contain heat-sensitive liquid crystals and expand and contract
    depending on the temperature.
  • They change colors according to the temperature.
Liquid Crystal Thermometers
Liquid Crystal Thermometers

3. Bulletproof vests-

  • Rigid polymers are oriented parallel to each other.
  • So tightly packed that they can easily withstand the impact of bullets.
Bulletproof vests
Bulletproof vests

Future with liquid crystals

With the rapid development of technology, liquid crystals are exhibiting the potential to turn our walls into large television screens! While this technology is already being employed in the science community and technological fairs, it won’t take much longer to make its way through every household’ just like smartphones. Smartphones too getting better every day. Screens have evolved not just in size but also with the mindboggling technology of curved screens and foldable screens.

Liquid crystals are something which includes all physical, chemical and biological applications hence all the main streams of science- physics, chemistry, biology, engineering- are working towards the betterment. All I can assure you now is this section of research and advancement is not going to get saturated anytime soon…

Also Read: Quantum Brain And Quantum Consciousness

Fardeen Ahmed

Fardeen Ahmed

He is a B.Sc. graduate and preparing for his Masters in Physics. He is a physics and philosophy enthusiast passionate about teaching Physics after completing his education. He's also a poet and has written many poems in English and Urdu.

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